Sub mainloop()
        Dim sendcmd() As Char = {Chr(153), Chr(3), Chr(192), Chr(54), Chr(0), Chr(2), Chr(4), Chr(29), Chr(10)}
        Dim sw As New Stopwatch
        Dim deleg As updatelabel
        Dim c As Long = 0
        Try
            sp.Open()
            deleg = New updatelabel(AddressOf updatelbl)
            Do Until st = True Or sp.IsOpen = False
                sendcomplete=false
                while not SendComplete
                    sw.Start()
                    sp.Write(sendcmd)

                    Do Until sp.BytesToRead >= 16 Or st = True Or sw.ElapsedMilliseconds > 99
                        System.Threading.Thread.Sleep(delay)
                    Loop

                    if sp.BytesToRead>=16 then
                        sendcomplete=true
                    else
                        sw.stop
                    endif

                end while
                Try
                    If sp.BytesToRead = 0 Then

                    End If
                    Dim intnumbytes As Integer = sp.BytesToRead
                    Dim bytCharData(intnumbytes - 1) As Byte
                    sp.Read(bytCharData, 0, intnumbytes)
                    sw.Stop()
                    sw.Reset()
                    Dim v1 As Integer = (bytCharData(14) And &HF) * 256
                    Dim v2 As Integer = bytCharData(15) + v1
                    c = c + 1
                    Me.Invoke(deleg, New Object() {v2, bytCharData(14), bytCharData(15), c})
                Catch invopex As InvalidOperationException
                    mainloop()
                Catch outofrangeex As IndexOutOfRangeException
                    MessageBox.Show("Please ensure the device is connected and there is no interference")
                Catch ex As Exception
                    MessageBox.Show(ex.ToString)
                End Try
            Loop
        Catch ioex As System.InvalidOperationException
            Exit Sub
        Catch ex As Exception
            MessageBox.Show(ex.ToString)
        End Try
    End Sub